Method of recording and reproducing picture information, recording medium, and recording medium playing apparatus

ABSTRACT

Method of recording and reproducing picture information and a recording medium on which the picture information is recorded by the method, and an apparatus for playing such a recording medium. In addition to video format signal and a coded information signal, graphic codes including picture information and instruction codes representing a mixing ratio on each position of a two-dimensional picture formed by the video format signal are recorded on the recording medium after being inserted as a subcode of the coded information signal. At the time of reproduction, signals according to the graphic codes are mixed at each position of the video format signal in accordance with the instruction codes. Preferably, in graphic codes are preferably codes representing the color of each position of the two-dimensional picture, and the instruction codes are codes respectively representing mixing ratios previously determined in accordance with colors represented by the graphics codes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of recording and reproducingpicture information on and from a recording medium such as a video disc,a digital audio disc, and so on, and a recording medium, and alsorelates to a recording medium playing apparatus.

2. Description of Background Information

In recording and reproducing contents of a movie source (or film source,in other words) on and from a recording medium such as a video disc, itis general to originally superimpose characters such as the translationof dialogues on the picture. Since the characters obtained by thisconventional method are always displayed without regard to the user'swill, such a display can be annoying for viewers in some occasions.Also, there have been a problem that it is necessary to prepare a masterdisc separately for each of different languages.

Accordingly, it is conceivable to adopt a method in which characters arecoded by means of the so-called closed caption system and the codedsignal is inserted in portions of a video format signal containing theinformation obtained from the movie (film) source which do not appear onthe display screen, such as the fly-back time portions, and inreproduction, the characters are reproduced by means of a decoderprepared for that purpose. With this method, the display of characterscan be enabled at need by an on-off control of the decoder of thatpurpose.

However, since the amount of data which can be inserted is relativelysmall in the closed caption method, and it is possible to displaysuperimposed characters only in one language. Therefore, there stillremains the problem that master discs must be prepared respectively foreach language.

On the other hand, a system is proposed in which picture information isrecorded and reproduced in the form of the subcode on and from a digitalaudio disc. The subcode is made up of eight subcode bits, and bit groupsforming the subcode are divided into eight channels denoted respectivelyby letters P, Q, R, S, T, U, V, and W. In the method in which thepicture information is recorded and reproduced in the form of subcode,data corresponding to picture information is configured such that asymbol is formed by 6 bits of channels R through W out of the 8 bitsforming the subcode, and 98 symbols are treated as one block, asillustrated in FIG. 1. Two symbols in the 98 symbols are used as a syncsignal, and 24 symbols obtained by dividing the remaining 96 symbols, byfour are treated as a minimum unit of data, i.e. a "pack", whichconstitutes one instruction of picture processing.

More specifically, the first symbol (referred to as symbol 0hereinafter) of the 24 symbols shows one of several modes. A symbol 1following this symbol 0 forms instruction which indicates the sort ofthe instruction. Symbols 2 and 3 following the symbol 1 constitute aparity Q which is an error correction code. Symbols 4 through 19following the parity Q constitute a data field, and include informationsuch as color information. Finally, symbols 20 through 23 following thedata field constitute a parity P which is an error correction code forprotecting the information in the "pack".

On the other hand, there are four modes, i.e. "zero mode","line-graphics mode", "TV-graphics mode", and "user's mode". The "zeromode" is provided for a case where no operation is required for pictureson the display screen, that is, the original image is to be maintained,and all data in the "pack" are 0 for this mode.

The "line-graphics mode" is provided for such a case that a liquidcrystal display is provided on the front face of the player, to displaynotes such as an explanation of a music selection. As shown in FIG. 2, apicture area being long sideways is formed by pixels which are arrangedin 288 columns and 24 rows. In other words, each row includes 288 pixelsand each column includes 24 pixels. The term "pixel" stands for theminimum display element of a picture, and it is general that the pictureprocessing is performed by using picture composing units designated as"fonts" each of which is made up of pixels divided into 6 columns and 12rows.

The number of "fonts" which can be displayed in the "line-graphics mode"is 48 in the lateral direction, and 2 in the column direction, and thisarea is designated as "screen area". For providing the scroll function,in line of "fonts" is added to the upper and lower outer peripheries andthe right and left peripheries of the Screen area, to form a picturearea having 50 "fonts" in the direction of row, and 4 "fonts" in thedirection of column. The subcode is formed so that the pictureprocessing is performed by using a memory having addresses eachcorresponding to each pixel in this picture area. In addition, the areaoutside the "screen area" is designated as "border".

The "TV-graphics mode" is a mode for displaying images on the TV screen,and a picture is formed by pixels arranged in 192 rows and 288 columnsas illustrated in FIG. 3. The number of "fonts" which can be displayedin the "TV-graphics mode" is 48 in the direction of row, and 16 in thedirection of column. Also in this "TV-graphics mode", the subcode isformed so that the picture processing is performed by using a memoryhaving addresses each of which corresponds to each pixel in a picturearea having 50 "fonts" in the direction of row, and 18 "fonts" in thedirection of column, made by adding a line of "fonts" to the upper endand lower peripheries as well as the right and left outer peripheries ofthe "screen area".

As instructions for the picture processing, there are an instruction forpainting out the whole picture area by one certain color, an instructionfor drawing a picture in one "font" on the screen by using two differentcolors, an instruction for moving the whole picture upward or sideways,and so on.

Additionally, in the 8-bit groups forming the subcode, the Q bitsforming the channel Q include time information corresponding to thetrack length to a certain position of each information data which isrecorded from the beginning of the program area of CD, and form addresstime data which can be used as positional data representing therecording position. On the other hand, the P bits forming the channel Pform data including information relating to a pause between two musicselections.

In the above-described system of recording and reproducing pictureinformation as subcode, the time period necessary for displaying apicture of one "font" is about 3.3/1000 second, and about 2.5 secondsare necessary for displaying 48×16 characters. This means that datacorresponding to 48×16 characters can be recorded in a track sectionwhich the pickup traces for 2.5 seconds, and such a recording capacityis sufficient for recording dialogues translated in several languages.However, with conventional recording and reproducing methods using thesubcode explained so far, the picture obtained from the subcode such ascharacters is displayed using the whole area of the screen. Therefore itwas not possible to view the picture obtained from the subcode such ascharacters, simultaneously with the picture obtained from the videoformat signal containing information obtained from a source such as amovie film, by superimposing the picture obtained from the subcode as asuperimposed dialogue.

OBJECT AND SUMMARY OF THE INVENTION

The present invention is based on the point described above, and anobject of the present invention is to provide a method of recording andreproducing picture information by which a large amount of dataincluding picture information such as characters can be recordedtogether with other information, and the recorded picture informationcan be selectively displayed in an area of a part of the picture formedby the video format signal.

Another object of the present invention is to provide a recording mediumon which picture information is recorded according to the method of theinvention, and an apparatus for playing such a recording medium.

A method of recording and reproducing picture information according tothe present invention is characterized by the steps of recording graphiccodes including picture information and instruction codes indicative ofa mixing ratio at each position on a two-dimensional picture formed bythe video format signal as the subcode of coded information signal, andat the time of reproduction, mixing signals according to the graphiccodes at each position of the video format signal according to thecontents of the instruction codes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing the recording format of subcode data;

FIG. 2 is a diagram showing the structure of picture in the"line-graphics mode";

FIG. 3 is a diagram showing the structure of picture in the "TV-graphicsmode";

FIG. 4 is a diagram showing the sort of recording modes in the methodaccording to the present invention;

FIG. 5 is a diagram showing the construction of "load transparencycontrol table";

FIG. 6 is a diagram showing the correspondency between the bit patternof TCB and the mixing ratio;

FIG. 7 is a diagram showing "load color look-up table color 0 throughcolor 7" instruction;

FIG. 8 is a diagram showing the construction of "write fontforeground/background" instruction;

FIG. 9 is a block diagram showing an example of the construction ofrecording apparatus;

FIG. 10 is a diagram showing recording area of a composite disc;

FIGS. 11A through 11C, when combined, are a block diagram showing anapparatus for reproducing picture information recorded on a disc inaccordance with recording and playback method according to the presentinvention;

FIG. 11 is a diagram showing the arrangement of FIGS. 11A through 11C;

FIG. 12 is a block diagram showing a specific configuration of videoformat signal processing circuit 30 in the apparatus shown in FIGS. 11Athrough 11C;

FIG. 13 is a flowchart showing the operation of processor in systemcontroller 32 of the apparatus shown in FIGS. 11A through 11C;

FIGS. 14 and 15A through 15C are diagrams showing pictures obtained bythe apparatus shown in FIG. 11A through 11C;

FIG. 16 is a diagram showing recording mode in another embodiment of thepresent invention;

FIG. 17 is a diagram showing the construction of "set TCW" instruction;

FIG. 18 is a diagram showing the construction of "write font"instruction;

FIG. 19 is a diagram showing the construction of "set TCW" instruction;and

FIG. 20 is a diagram showing the construction of "pre-set memory"instruction.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

An embodiment of the method according to the present invention will beexplained with reference to FIGS. 4 through 19 of the accompanyingdrawings.

As shown in FIG. 4, a code to be inserted as the symbol 0 is set inorder to designate an additional mode, that is, "graphic mode withmotion picture" in addition to the "zero mode" the "line-graphics mode",the "TV-graphics mode" and the "user's mode" which are also used inconventional methods.

The structure of picture in the "graphics mode with motion picture" isidentical with that in the "TV-graphics mode", and an instructiondesignated as "load transparency control table" is provided. This "loadtransparency control table" instruction is an instruction fordesignating the mode for each pixel in picture area. Three modes aredesignated by this instruction, and those are namely, "transparentmode", "mixing mode", and "non-transparent mode". In these three modes,different values are selected for the mixing ratio between a videoformat signal obtained by the subcode and a video format signal which isrecorded by multiplexing together with the coded information signalincluding the subcode.

The bits in the channels R through W of each of the symbols 4 through 8and the channels R and S of the symbol 9 constitute a series of codesTCB-0 through TCB-15 which respectively designate one of modes whichwill be described later for each of the group of pixels to which one ofcolors, which are registered as color number "0" through color number"15", is allotted. FIG. 6 shows a relationship between bit pattens ofthe codes TCB-0 through TCB-15 and the modes designating the mixingratio, and the mixing ratio in each mode.

In addition, the sixteen colors indicated by the color number "0"through "15" are set by a "load CLUT color 0 through color 15 (loadcolor look-up table color 0 through color 15)" instruction. The "loadCLUT color 0 through color 15" instruction is an instruction having astructure illustrated in FIG. 7, and setting the contents of a colorlook-up table showing the color of pre-set color numbers orforeground/background color numbers. It is necessary to designatesixteen colors in total. However, since four bits are used respectivelyfor each of RGB to indicate a color, two symbols are required forsetting one color. Therefore, eight colors are set by one "pack" atmost. With this circumstances, this instruction is divided into twoinstructions respectively designating eight colors of the first half,and eight colors of the second half.

The instruction code for the colors of the first half, i.e. the color 0through the color 7, is determined to be "30", and the instruction codefor the colors of the second half, i.e. the color 8 through color 15 aredetermined to be "31". The mixing of colors for each of the color numberis as follows. Red color is represented by four bits of the channels Rthrough U of even symbols allotted to the color number. Green color isrepresented by four bits, i.e. two bits of the channels V and Wfollowing the channels R through U of the even symbols, and two bits ofthe channels R and S of odd symbols. Blue color is represented by fourbits of channels T through W following the channels R and S of the oddsymbols. Therefore, 2⁴ (=16) sorts of gray scales are available for eachcolor, and preparation of 16³ (=4096) colors is possible since threecolors (RGB) are used. In addition, a gray scale "0000" corresponds tothe darkest state, and a gray scale "1111" corresponds to the brigheststate.

On the other hand, a "write font foreground/background" instruction isused in the "TV-graphics mode", which has such a structure asillustrated in FIG. 8. This is an instruction for writing font data ofthe symbols 8 through 19 in positions having a row address defined bythe symbol 6 and a column address defined by the symbol 7. For thepixels whose font data is "0", a color of a color number determined bythe "color 0" is designated as a background color. For the pixels whosefont data is "1", a color of a color number defined by "color 1" isdesignated as a foreground color. At the same time, subpicture channelscan be designated by using four bits of the channels R and S of thesymbols 4 and 5. By this feature, as many as sixteen picture channelscan be designated. Sixteen sorts of picture are previously recorded on adisc for example, and on the playing side, a desired picture channel canbe selected at the time of playing by this scheme of designating thepicture channel.

FIG. 9 shows an apparatus for recording the above explained codes on arecording disc by inserting the codes in the subcode.

In the arrangement shown in FIG. 9, two-channel audio signals and avideo format signal outputted from a video tape recorder for example,are respectively supplied to input terminals IN₁, IN₂, and IN₃. Thevideo format signal is supplied to an FM modulator 1. In the FMmodulator 1, a carrier signal of a predetermined frequency isFM-modulated by the video format signal. An FM signal outputted by thisFM modulator 1 is supplied to a multiplexing circuit 3. On the otherhand, left and right-channel audio signals are supplied to ananalog-to-digital converting circuit 4. The analog-to-digital convertingcircuit 4 is configured to perform the sampling of each of the left andright-channel audio signals at a sampling frequency of 44.1 MHz forexample, to generate two digital data corresponding to two sampledvalues obtained by the sampling, and to output the digital data aftertreating them by time division multiplexing. The output data of this A/Dconverter 4 is supplied to a CD system encoder 6 through an errorcorrection code adding circuit 5 which performs the interleave of thedata, the error detection, and addition of codes for the errorcorrection. To the CD system encoder 7, an output singal of the controlsignal generating circuit 7 and an output signal of the error detectionand correction code adding circuit 8 are supplied. The control signalgenerating circuit 7 is configured to generate data such as a dataindicating the time elapsed after the start of the supply of audiosignals to the input terminals IN₂ and IN₃, and a data indicating apause between music selections or a portion within one music selectionof the audio signals.

On the other hand, output data of the graphic/instruction codegeneration device 9 is supplied to the error correction and correctioncode adding circuit 8. The graphic/instruction code generation device isconfigured to record a plurality of codes which are previously inputtedby key operations for example, and to read-out and output desired codes.The error detection and correction code adding circuit 8 is configuredto perform the interleave and error detection of the output data of thegraphic/instruction code generation device 9 and the addition of thecorrection code.

The CD system encoder 6 is configured to form a recording signal bymaking the output of the control signal generation circuit 7 data of thechannels Q and P, and making the output of the graphic code generatingdevice through the error detection and correction code adding circuit 8data of the channels R through W, and inserting those data into thedigital data from the A/D converter 4. Output signal of this CD systemencoder 6 is supplied to a modulator 10 and converted to an EFM (Eightto Fourteen Modulation) modulation signal. The output signal of thismodulator 10 is supplied to the multiplexing circuit 3, and processed bya frequency multiplexing with the FM-modulated video format signal.

The output signal of the multiplexing circuit is supplied to an opticaldisc recorder of known arrangement (not shown) in which the strength ofa light beam irradiated on the recording surface of a disc rotated at aconstant linear velocity for example, is modulated by this signal. As aresult, the graphic codes including picture information and theinstruction codes are recorded on the recording disc as the subcode ofthe digital audio signal, in addition to the video format signal and thedigital audio signal as the coded information signal.

FIG. 10 shows a composite disc 20 carrying a digital audio signalfunctioning as the coded information signal into which the subcodeincluding picture information is inserted as explained above. As shown,the composite disc 20 has a first area 20a disposed in an innerperipheral area of the disc (this area being referred to hereinafter asthe CD area) in which is recorded a digital audio signal with thesubcode including picture information being inserted, and a secondrecording area 20b (this area being referred to hereinafter as the videoarea) containing an FM-modulated video format signal and a superimposeddigital audio signal with the subcode including picture informationbeing inserted, wherein the superimposition is performed by using afrequency multiplexing system. Since the video format signal containshigher frequency components than the PCM signal, it is necessary torotate the disc at a higher speed of rotation during the recording ofsignals in the video area 20b, than during the recording of the signalin the CD area 20a. Therefore of course it is necessary, in the playingtime, to reproduce the signal by rotating the disc at the higher speedduring the playback of video area 20b, than during the playback of CDarea 20a. The speed of disc rotation during the playback of CD area 20ais several hundred r.p.m., whereas during the video area playback thespeed of rotation is two thousand plus several hundred r.p.m. forplayback from the innermost periphery of that area, and is one thousandplus several hundred r.p.m. for playback from the outermost periphery ofthat area, so that the speed of rotation is extremely high during videoarea playback.

In the head portions of the CD area 20a and the video area 20b, thererespectively are provided a lead-in area in which are recorded, as thesubcode, index codes relating to the contents recorded in each area,such as first and second code groups formed correspondingly to each areaby the repetition of index codes which respectively indicate start andend times of small portions which together constitute each area. Inaddition, the index codes of the audio lead-in area include informationshowing whether the disc itself is a composite disc or a disc of othertype.

FIGS. 11A through 11C show a disc player for playing a composite discwhich has been explained above. As illustrated in these figures, a disc20 is rotated by a spindle motor 21, and information recorded thereon isread-out by means of a pickup 22. The pickup 22 incorporates therein anoptical system, including a laser diode, and objective lens, and photodetectors, a focus actuator for driving the objective lens in adirection of its optical axis with respect to the information recordingsurface of the disc 20, a tracking actuator for biasing the beam spot(information detecting point) issued from the pickup 22 with respect tothe recording tracks in a direction of disc radius, and so on. Thepickup 22 is mounted on a slider 23 which is movable in the direction ofdisc radius by a direct drive of a transmission mechanism 25 which inturn has a slider motor 24 as a source of driving force, and made by acombination of rack and pinion gears. A read-out RF (radio frequency)signal outputted by the pickup 22 is supplied to a video format signaldemodulating and processing circuit 30 and a coded informationdemodulating and processing circuit 31 through an RF amplifier 26.

The video format signal demodulating and processing circuit 30 includesa demodulation circuit which for example demodulates the RF signal andconverts it to a video format signal and a memory which stores the videoformat signal after digitizing it, and configured to selectively outputone of the video format signal outputted by the demodulation circuit andthe video format signal read-out from the memory in accordance with achangeover command from a system controller 32. The video format singaloutputted by the video format signal demodulating and processing circuit30 is supplied to a video switch 33. In addition, the video formatsignal demodulating and processing circuit 30 is further provided with aseparating circuit which separately extracts a horizontal sync signal h,a vertical sync signal v, and control data c from the demodulated videoformat signal, and the separated horizontal and vertical sync signals hand v, and the control data c are supplied to each part such as thesystem controller 32.

On the other hand, the coded information demodulating and processingcircuit 31 is provided with a selector switch 35 which changes itsswitch position in accordance with the area to be played (the CD area orthe video area) during the playing of a composite disc. The selectorswitch 35 is operated to a position a during the playing of the CD area,and to a position b during the playing of the video area, and thechangeover is performed in response to a changeover command issued fromthe system controller 32. In the case of the composite disc, the speedof disc rotation changes extremely between the CD area and the videoarea, and the PCM audio signal is for example an EFM (Eight to FourteenModulation) signal. For the video area, the EFM signal will adverselyaffect on the low frequency component of the video signal treated by theFM modulation process if the digital signal is directly superimposed onthe FM video signal at the time of recording. Therefore, the digitalsignal, i.e. the EFM signal is recorded at a level which is lower thanthe video carrier level by several tens of dB, although the degree ofmodulation is almost the same for the EFM and video signals. Thus thefrequency characteristic and amplitude of a playback EFM signal willboth be different, for the cases of CD area playback and video areaplayback respectively. However, a common demodulating system is used forthe CD area playback and the video area playback. This is made possibleby switching signal processing systems for the playback EFM signals ofthe CD area and the video area respectively.

Specifically, during playback of the CD area, the playback RF signal isan EFM signal, which is subjected to frequeancy characteristiccompensation by an equalizer circuit 36 having a predeterminedequalizing characteristic, and is amplified at a predeterminedamplification factor by an amplifier 37. During the playing of the videoarea, on the other hand, the playback RF signal is an FM video signalwhich is combined with an EFM signal. The EFM signal is extracted by anEFM signal extracting circuit 38 which is made up of an LPF and so on,then is subjected to frequency characteristic compensation by anequalizer circuit 39, which has a different equalization characteristicfrom the equalizer circuit 36, to be then amplified by an amplifier 40,which has a higher gain than that of the amplifier 37. In this way, anEFM signal is derived whose frequency characteristic and amplitude arealmost the same as the EFM signal obtained during CD area playback.

During playback of a CD disc, the selector switch 35 is held in positiona.

The playback EFM signal selected by the selector switch 35 is suppliedto an EFM demodulation circuit 42 which performs the demodulationprocess, to obtain a PCM daata that is digital data including audioinformation of left and right channels which is for exampletime-division multiplexed, and the subcode. The digital data includingaudio information outputted by this EFM demodulation circuit 42 issupplied to a de-interleave and interpolating circuit 43. Thede-interleave and interpolating circuit 43 is configured to change back,in cooperation with the RAM 44, the order of the digital data which wasrearranged by the interleave operation during the recording, in turnsend it to an error correction circuit 45, and to effect theinterpolation of erroneous data in the output data of the errorcorrection circuit 45 by the average value interpolation method forexample, when a correction inabilty signal is outputted. The errorcorrection circuit 45 is configured to perform the error correctionoperation by using the CIRC (Cross Interleave Reed Solomon Code), andsupply the digital data to the de-interleave and interpolating circuit43, or supply the digital data to the de-interleave and interpolatingcircuit 43 together with the correction inability signal when the errorcorrection is not possible.

The output data of the de-interleave and interpolating circuit 43 issupplied to a D/A (Digital to Analog) converting circuit 46. The D/Aconverting circuit 46 includes a de-multiplexer which separates fromeach other the digital data of left and right-channel audio informationcombined by the time division multiplexing, and left and right-channelaudio signals are reproduced. After their unnecessary components areremoved at LPFs (Low Pass Filter) 47 and 48, the reproduced left andright-channel audio signals are supplied to audio output terminals OUT₁and OUT₂ through amplifiers 49 and 50.

On the other hand, in the subcode outputted by the EFM demodulatingcircuit 42, two bits of the channels P and Q are supplied to the systemcontroller 32, and six bits of the channels R through W are supplied toa de-interleave and error correction circuit 52 in which thede-interleave of the six bits of the channels R through W and the errorcorrection using the parity Q and P are performed. Output data of thede-interleave and error correction circuit 52 is supplied to amode/instruction decoder 53. The mode/instruction decoder 53 isconfigured to decode the mode represented by the three bits of thechannels R through T of the symbol O of each pack, the mode designatedby the item represented by the three bits of the channels U through W ofthe symbol O of each pack, and the instruction represented by the sixbits of the channels R through W of the symbol 1 of each pack, and tosupply to each part signals respectively indicative of the modes and theinstruction.

Furthermore, the output data of the de-interleave and error correctioncircuit 52 is supplied to a picture memory device 55. The picture memorydevice 55 includes sixteen RAMs 56a through 56p having addressesrespectively corresponding to all pixels on a picture having 50 "fonts"by 18 "fonts" in the row and column directions, and four bits of datacan be stored in each address, and a memory control circuit 57 forsensing data indicating the color number of each pixel of each picturechannels in the output data of the de-interleave and error correctioncircuit 52 by using the kind of the modes and the instruction indicatedby the output of the mode/instruvtion decoder 53 and writing them in thecorresponding addresses of the RAMs 56a through 56p, and for reading outsequentially in a predetermined order one memory content of the RAMs 56athrough 56p corresponding to the picture channel designated by a data dby the key operation in an operation part 60 in accordance withhorizontal and vertical sync signals h and v.

The data outputted by the picture memory device 55 is supplied to acolor look-up table 58 (this table being referred to hereinafter as theCLUT). The CLUT 58 is configured to detect the "load CLUT color Othrough color 7" instruction and the "load CLUT color 8 through color15" instruction from the output data of the de-interleave and errorcorrection circuit 52 in accordance with the kind of the modes and theinstruction indicated by the output signal of the mode/instructiondecoder 53, and hold the color data corresponding to each color number,and configured to select and output color data of the color numberdesignated by the data read-out from the picture memeory 55.

The output data of this CLUT 58 is made up of three data respectivelyrepresenting the level of one of the R, C, B color signals by using fourbits. The three data outputted by the CLUT 58 and indicating the levelsof the R, G, B color signals are supplied to D/A converting circuit 61,62, and 63, and converted to analog signals. Output signals of these D/Aconverting circuits 61 through 63 are supplied to an analog-to-videoconverting circuit 65. The analog-to-video converting circuit 65 isconfigured, for example, to form a video signal of the NTSC system bythe steps of obtaining a luminance signal and two color differencesignals by the output signals of the D/A converting circuits 61 through63, generating a color carrier signal by adding signals obtained by theparallel modulation of two color subcarrier signal having a phasedifference of 90° by means of the two color difference signals, andcombining the color carrier signal and the luminance signal by thesummation, and adding sync signals thereto. By this analog-to-videoconverting circuit 65, the output signals of the D/A converting circuits61 through 63 are converted to a video signal and sent subsequently.

In addition, the output data of the de-interleave and the errorcorrection circuit 52 are also supplied to a transparency control table66 (this table being referred to hereinafter as the TCT). The TCT 66 isconfigured to detect a "load TCT" instruction in the output data of thede-interleave and error correction circuit 52 in accordance with thekind of the modes and instruction indicated by the output signal of themode/instruction decoder 53, hold transparency control bits TCB-0through TCB-15, and output by selecting one of the TCB-0 through TCB-15being held, corresponding to a color number indicated by the dataread-out from the picture memory device 55.

The output signal of the TCT 66 is supplied to a video switch 33 as acontrol signal. In addition to the output signal of the TCT 66, thevideo format signal obtained from the subcode and outputted by theanalog-to-video converting circuit 65, and the video format signaloutputted by the video format signal demodulating and processing circuit30 are supplied to the video switch 33.

In the video switch 33, the video format signal obtained from thesubcode is supplied to a stationary contact x of the changeover switch68, and also supplied to its stationary contact y through a resistor R₁.No connection is made to a stationary contact z of the changeover switch68. The changeover switch 68 is configured to selectively output one ofthe signals supplied to its stationary contacts x, y, z by moving itsmovable contact u to be in contact with one of the stationary contactsx, y, z in accordance with a control signal issued from the TCT 66. Thevideo format signal outputted from the video format signal demodulatingand processing circuit 30 is directly supplied to a stationary contact zof a changeover switch 69 and also supplied to its stationary contact ythrough a resistor R₂. No connection is made to a stationary contact xof the changeover switch 69. The changeover switch 69, like thechangeover switch 68, is configured to move its movable contact u to bein contact with one of its stationary contacts x, y, z in accordancewith the control signal. The movable contacts u, u of the changeoverswitches 68 and 69 are mutually connected. A resistor R₃ is connectedbetween a common junction J of the movable contacts u, u and ground. Amixed signal of the video format signal obtained from the subcode andthe video format signal outputted from the video format signaldemodulating and processing circuit 30 is derived at the common junctionJ. When the movable contacts u, u of the changeover switches 68 and 69are in contact with the stationary contacts x, x respectively, themixing ratio of the video format signal obtained from the subcodebecomes 100%, and the mixing ratio is reduced to 0% when the movablecontacts u, u are in contact with the stationary contacts z, z. When, onthe other hand, the movable contacts z, z are in contact with thestationary contacts y, y, the mixing ratio is equal to M which isdetermined by the resistors R₁ and R₂, and the resistance of theresistors R₁ and R₂ are selected so that M has a value between 20% and80%. The signal derived at the common junction J is supplied to a videooutput terminal OUT₃.

A position detector 70 is provided in the vicinity of the path of themovement of pickup 22 along the radial direction of disc, and serves todetect when the beam spot emitted from the pickup 22 has reached aposition corresponding to the vicinity of the boundary between the CDare and the video area of a composite disc, to produce a detectionsignal. By the generation of this detection signal, a state that thepickup 22 has reached to the video area can be detected. The positiondetector 70 can have a known structure including for example an opticalsensor. The detection signal outputted by the position detector 70 issupplied to the system controller 32.

The system controller 32 comprises a microcomputer which consists of aprocessor, a ROM (read only memory), a RAM and so on. The systemcontroller 32 is supplied with various signals and information such asthe horizontal sync signal h, the vertical sync signal v, and thecontrol data c, the P-channel and Q-channel bits in the subcodeoutputted from the EFM demodulation circuit 42, disc designationinformation from the control part 60 indicating whether the disc to beplayed is a compact disc or a composite disc, and mode designationinformation from the operation part 60, indicating whether thereproducing area is only the CD area or the video area, or both CD andvideo areas in the case of the playback of a composite disc.

In this system controller 32, the processor executes processing of thesignals inputted in accordance with programs previously stored in theROM, and performs the control operation of each part of the video formatsignal demodulating and processing circuit 30, the selector switch 35, adrive circuit (not shown) for driving the spindle motor 21, the drivingcircuit 71 for driving the slider motor, and the display part 72.

FIG. 11 is a block diagram showing a specific circuit construction ofthe video format signal demodulating and processing circuit 30. Asshown, the RF signal from the RF amplifier 26 is demodulated at ademodulation circuit 75, then supplied to a time base correction circuit76 and to a separator circuit 77. In the separator circuit 77, thehorizontal sync signal h, the vertical sync signal v and the controldata c which are contained in the video format signal are extracted. Thetime base correction circuit 76 consists of, for example, a variabledelay element of e.g. CCD (charge coupled device) and configured to varythe delay amount of that element in accordance with a control signalfrom a time base control circuit 78. The time base control circuit 78 isconfigured to output as the control signal a signal corresponding to aphase difference between an oscillation signal and its divided signal ofa crystal oscillator (VCO) 79 which oscillates, for example, insynchronism with the horizontal sync signal h extracted at the separatorcircuit 77, and the horizontal sync signal and the color burst signal ofthe video signal transmitted through the time base correction circuit76. For more specific configuration, reference is directed for exampleJapanese patent application laid-open number P56-102182.

The video signal having been processed by the time base correctionoperation is used as one input of a selector switch 80, and alsosupplied to an A/D converter 82 through an LPF (Low Pass Filter) 81. Inthe A/D converter 82, the sampling of the video signal is performed atintervals of a predetermined period, and the thus obtained sampledvalues are in turn converted to digital data. The output data of the A/Dconverter 82 is supplied to a video memory 83 consisting of a RAM(random access memory) and so on. A memory having a capacity for storingvideo information of at least one field long is used as the video memory83. Address and mode controls of this video memory 83 are performed by amemory control circuit 84. The memory control circuit 84 is configuredto perform control operations for sequentially read-out data written ineach address of the video memory 83 in accordance with a clock from areference clock generating circuit 85, and for rewriting the contents ofeach address of the video memory 83 in response to a write enable signalw which is outputted from the system controlled 32. The data read-outfrom the video memory 83 is converter to an analog signal in a D/A(digital to analog) converter 86, and supplied through an LPF 87 as theother input to the selector switch 80. The selector switch 80 isnormally held at a position a to selectively output the video formatsignal directly supplied from the time base correction circuit 76, andswitched to a position b in response to a changeover command from thesystem controller 32, to selectively output the video format signalhaving been processed through the video memory 83.

Operations of the processor in the system controller 32 in the aboveconfiguration will be specifically explained with reference to theflowchart of FIG. 13.

Assume that a composite disc is set in a playback position. When a startcommand is issued in this state, the processor transmits a drive commandto the motor driving circuit 71, so that the slider motor 24 is drivento move the pickup 22 to an innermost peripheral position (step S1). Ifit is detected that the pickup 22 has reached the innermost peripheralposition by means of a detector switch of any usual configuration (notshown), the processor executes a focusing operation of the pickup 22,and performs the read-in of index code information which is recorded inan audio lead-in area at an innermost peripheral area of the disc (stepS2). Subsequently, the processor judges whether or not the disc beingset is a composite disc or not, on the basis of the read information(step S3). If it is judged that the disc being set is a compact disc,then the execution directly proceeds to a CD playback mode (step S4) anda playback operation is continuously performed unless any command forthe programmed music selecting operation for example has been issued.Since the playback operation in the CD playback mode itself is wellknown, the explanation thereof is omitted here.

If it is judged in the step S3 that the disc being set is a compositedisc, the processor immediately accelerates the slider motor 21 to amaximum rated speed of rotation for the video area (step S5). At thesame time, the processor moves the pickup 22 toward the outer peripheryof disc at a high speed by driving the slider motor 24 at a high speed(step S6). After these operations, when it is detected that the pickup22 has reached to the video area by the detection signal from theposition detector 70 (step S7), the processor starts the playbackoperation of the video area (step S8). During video area playback, theprocessor performs the control operation for writing the videoinformation of at least one field (or one frame) long obtained from thedisc in the video memory 83. This video information to be written maybe, for example, first information in the video area, or designated byand address designation through the key operation of the operation part60.

If it is detected that the playback of the video area has beencompleted, in step S9, then the processor decelerates the spindle motor21 to the maximum rated speed of rotation for the CD area (step S10). Atthe same time, the processor drives the slider motor 24 at a high speed,to move the pickup 22 to the innermost peripheral position of the discat a high speed (step S11). If it is detected (step S12) that the pickup22 has reached the innermost peripheral position by the detection outputsignal of the above mentioned detector switch (not illustrated), theprocessor starts playback operation of the CD area (step S13).Concurrently to this, the selector switch 80 in the video format signaldemodulating and processing circuit 30 is changed over by the processorto the position b thereby selecting and outputting the video informationwhich was written in the video memory 83 during video area playback.Thus, playback of a still picture is performed during CD area playback.When the completion of the CD area playback is detected by reading theinformation of audio lead-out (step S14), the processor initiate thedriving of the slider motor 24 to move the pickup 22 to its homeposition (step S15) unless any operational command is present.Furthermore, a loading mechanism (not shown in the drawings) performsdisc ejection (step S16), to complete the playback operating sequence.

In the operating sequence described above, playback of the informationrecorded in the CD area of the composite disc is performed in steps S10through S14 after the playback of information recorded in the video areain steps S1 through S9. When the "load CLUT color 0 through color 7"instructions and the "load CLUT color 8 through color 15" instructionsare decoded by the mode/instruction decoder 53 during video areaplayback, data of designated 16 colors among 4096 colors are held in theCLUT 58.

Subsequently, by the decoding of the "write font foreground/background"instruction etc., picture data of 16 channels are in turn stored in theRAM 56a through 56p in the picture memory device 55. When one of thepicture data of 16 channels is designated by data corresponding to thekey operation in the operation part 60, picture data of the designatedchannel is sequentially outputted from the picture memory device 55, andin turn supplied to the CLUT 58. By this operation, color data of acolor number indicated by the picture data is then outputted from theCLUT 58. A video format signal based on this color data is outputtedfrom the analog video converting circuit 65, and supplied to the videoswitch 33.

If the "load TCT" instruction is decoded in this state, the transparencycontrol bits TCB-0 through TCB-15 respectively corresponding to eachcolor number are then held in the TCT 66. Among the TCB-0 through TCB-15being held, one corresponding to the color number indicated by the dataread-out from the picture memory device 55 is selectively outputted fromthe TCT 66, and the mixing ratio in the video switch 33 is designated bythe output of the TCT 66. Thus, the mixing ratio between the videoformat signal outputted from the analog-to-video converting circuit 65and the video format signal outputted from the video format signaldemodulating and processing circuit 30 is controlled for each pixel.Consequently, a combination of pictures such as illustrated in FIG. 14is made possible. Specifically, the mixing ratio is set to 100% for aportion corresponding to each pixel outside a region D of a picture Abased on the video format signal outputted from the video format signaldemodulating and processing circuit 30, and set to 0% for a portioncorresponding to each pixel within the region D. On the other hand, themixing ratio is set to 0% for a portion corresponding to each pixeloutside a region D' of a picture B based on the video format signaloutputted from the analog-to-video converting circuit 65, and set to100% for a portion corresponding to each pixel within the region D' ofthe picture B. Then a picture C can be formed by combining the portionof the picture A outside the region D and the portion of the picture Bwithin the region D'.

In this way, it is possible to compose a picture as illustrated in FIGS.15A through 15C, in which a translation of a dialogue, a musical score,or an explanation of a scene, etc., obtained from the subcode isinserted into a moving picture obtained by the video format signalrecorded in the video area.

Moreover, by inserting data corresponding to characters of a pluralityof languages in each of the picture channel, it becomes possible torecord captions (translations of dialogues) in a plurality of languagesin a single disc, and to selectively display the caption (translation ofdialogues) in a desired language in accordance with a key operation inthe operation part 60. Thus, the preparation of a plurality of motherdiscs for different languages is no more required.

FIG. 15 is a diagram showing another embodiment of the presentinvention. In this embodiment, codes to be inserted as the symbol 0 areset for designating "extended ling-graphics mode" and "extendedTV-graphics mode" in addition to the four modes of "zero mode","line-graphics mode", "TV-graphics mode", and "user's mode" in theconventional system.

The composition of picture in the "extended line-graphics mode" is thesame as in the "line-graphics mode", and an instruction designated by a"set TCW" (set Transparent Control Word) having a structure shown inFIG. 17, and an instruction designated as "write font" shown in FIG. 18are provided. The "set TCW" instruction is such an instruction in whicheach of the bits b₀ through b₇ of TCW represented by 8 bits of thechannels T through W of the symbols 4 and 5 corresponds to each of thecolor numbers indicative of the eight colors in the "line-graphicsmode", and which sets the mixing ratio to either one of 0% and 100% foreach of the groups of pixels to which the corresponding color number isdesignated respectively, by using the value of the bits b₀ through b₇.On the other hand, the "write font" instruction, like the "write font"instruction in the "line-graphics mode", is an instruction for writingthe font data in the designated locations in the picture memory, and atthe same time, setting the mixing ratio to either one of 0% and 100% foreach of groups of the pixels to which two color numbers representedrespectively by 3 bits of the channels U through W of the symbols 4 and5 are designated, by means of the value of each of the bits T₀, T₁ ofthe channel T of the symbols 4 and 5.

The composition of picture in the "extended TV-graphics mode" is thesame as in the "TV-graphics mode", and this mode is provided with theinstruction designated as "set TCW" illustrated in FIG. 19, and aninstruction designated as "pre-set memory" illustrated in FIG. 20. The"set TCW" instruction in the "extended TV-graphics mode" is such aninstruction in which bits b₀ through b₁₅ of the TCW represented by 16bits of the channels T through W of the symbols 4 through 7 respectivelycorrespond to the color numbers indicating the 16 colors in the"TV-graphics mode", and which sets the mixing ratio to either one of 0%and 100% for each of groups of pixels to which corresponding colornumber is designated, by using the value of each of the bits b₀ throughb₁₅. The "pre-set instruction" instruction, on the other hand, is aninstruction for setting the mixing ratio to either one of 0% and 100%for each of groups of pixels to which colors of the color numbersrepresented by the four bits of the channels T through W of the symbol 4are designated respectively, by using the value of the bit T of thechannel R of the symbol 4.

The picture information recorded as the subcode using the recordingformat explained so far can be processed by making the configuration ofthe TCT 66 in the apparatus shown in FIGS. 11A through 11C such thatdata representing the mixing ratio is held correspondingly to each colornumber by means of the "set TCW" instruction, the "write font"instruction, and the "pre-set memory" instruction.

In the embodiment described above, the recording medium on which thesubcode carrying picture information is recorded is a composite discgenerally designated as CDV. However, it is of course possible to use,as the recording medium on which the subcode carrying the pictureinformation is to be recorded, other type of recording medium such as adisc designated as LDD i.e. a disc on which an FM-modulated video formatsignal, an audio signal, and a digital audio signal are recorded bymultiplexing, by using a frequency multiplexing system, and so on.

Furthermore, in the embodiment described above, the number of bits ofthe instruction codes indicating the mixing ratio in each position oftwo-dimensional picture formed by the video format signal, is describedas 1 or 2. However, the number of bits of this instruction codes can beset to be any value as long as the number does not exceeds the bitnumber of the data field in one pack.

In the above described embodiment, new modes such as the "graphic modewith picture", "extended line-graphics mode", "extended TV-graphicsmode", are provided, and the instructions for designating the mixingratio in each pixel are provided only in these new modes. However, it isalso possible to arrange such that the instructions for designating themixing ratio in each pixel are added, for example, in the "TV-graphicsmode", without providing any new mode. As the instruction to be added inthe "TV-graphics mode", an instruction having such a construction asshown in FIG. 5, or an instruction like the instruction shown in FIG. 20in which the mode of each pixel can be set to either one of thetransparent mode and the non-transparent mode by the 16 bits of thechannels T through W of the symbols 4 through 7, and the mode in eachpixel can be set to a mixing mode by using 16 bits of the channels Tthrough W of the symbols 8 through 11. In the case of the latterinstruction, it is preferable to make valid only a part of the bits inthe symbols 8 through 11, which correspond to the bit "1" among the bitsin the symbols 4 through 7.

As explained in detail in the foregoing, the method of recording andreproducing picture information according to the present invention isconfigured such that graphic codes including picture information andinstruction codes indicative of the mixing ratio at each position of atwo-dimensional picture formed by a video format signal are inserted assubcode of a coded information signal and record on a recording medium,and in reproduction, a signal according to a graphic code is mixed atpositions of the video format signal in accordance with the instructioncodes. By this feature, it is possible to record large amount of dataincluding picture information such as characters with other information,and to selectively display the recorded picture information in a regionof a part of the picture formed by the video format signal.

What is claimed is:
 1. A method of recording and reproducing pictureinformation on a recording medium comprising the steps of:insertinggraphic codes including picture information and instruction codes as asubcode of a coded information signal, wherein each of said instructioncodes indicates a mixing ratio between a picture according to a videoformat signal and a picture according to said graphic codes at eachposition of a two-dimensional picture formed by said video formatsignal; recording said coded information signal on said recordingmedium; and mixing, at a time of reproduction from said recordingmedium, signals based on said graphic codes at each position of saidvideo format signal in accordance with contents of said instructioncodes.
 2. A method as set forth in claim 1, wherein said graphic codesrepresent the color of each position of said two-dimensional picture,and said instruction codes respectively represent one of mixing ratioswhich are previously determined correspondingly to colors represented bysaid graphic codes.
 3. The method claimed in claim 1, wherein said videoformat signal is recorded with said coded information signal on saidrecording medium in the recording step.
 4. An apparatus for playing apicture information recording medium on which are recorded graphic codesincluding picture information and instruction codes, said codes beinginserted as a subcode of a coded information signal, wherein each ofsaid instruction codes indicates a mixing ratio between a pictureaccording to a video format signal and a picture according to saidpicture information by said graphic codes at each position of atwo-dimensional picture formed by said video format signal, saidapparatus comprising:pickup means for reading signals recorded on saidrecording medium and generating a pickup output signal; codedinformation signal demodulating means for demodulating said codedinformation signal from said pickup output signal; graphic codesdemodulating means for demodulating said graphic codes from an outputsignal of said coded information signal demodulating means; instructioncodes demodulating means for demodulating said instruction codes fromsaid output signal of said coded information signal demodulating means;means for generating signals based on said graphic codes from an outputsignal of said graphic codes demodulating means; and mixing means formixing said signals based on said graphic codes at each position of saidvideo format signal in accordance with contents of said instructioncodes.
 5. An apparatus as set forth in claim 4, wherein said graphiccodes represent the color of each position of said two-dimensionalpicture, and said instruction codes respectively represent one of mixingratios which are previously determined correspondingly to colorsrepresented by said graphic codes.
 6. The apparatus as claimed in claim4, wherein said video format signal is recorded on said pictureinformation recording medium and the apparatus further comprises videoformat signal demodulating means for demodulating said video formatsignal from said pickup output signal.